Silver halide photographic emulsion

ABSTRACT

and at least one organic heterocyclic compound selected from the formulas represented by the general formulas II and III, wherein   Silver halide photographic emulsion comprising at least one sensitizing dye represented by general formula I: The substituent moieties shown in the above groups are described in the specification.

United States Patent [54] SILVER HALIDE PHOTOGRAPHIC EMULSION 4 Claims, 2 Drawing Figs.

[52] U.S. Cl 96/126, 96/102, 96/104, 96/106 [51] Int. Cl G03c l/28 [50] Field of Search 96/ 104,

[56] References Cited UNITED STATES PATENTS 3,173,791 3/1965 Kaleda 96/104 3,264,110 8/1966 Depoorter et al..... 96/106 3,268,334 8/1966 DePoorter et al. 260/2406 X 3,397,060 8/1968 Schwan et al 96/104 Primary Examiner-William D. Martin Assistant Examiner-Theodore G. Davis Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak RELATIVE SPEED ABSTRACT: Silver halide photographic emulsion comprising at least one sensitizing dye represented by general formula I:

and at least one organic heterocyclic compound selected from the formulas represented by the general formulas II and [[1, wherein general Formula II is:

and general Formula III is:

The substituent moieties shown in the above groups are described in the specification.

WAVE LENGTH (mp) PATENTEDUCI 2 s 1971 3,615.6 3 5 Q E FIG. I 2 5 v Ii] I I I I I l WAVE LENGTH (mp) 5% FIG. 2 g

m I I I I I I WAVE LENGTH (mp) INVENTORS KEISUKE SHIBA AKIRA SATO BY ATTORNEYS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a spectrally sensitized silver halide photographic emulsion and more particularly to a super-sensitized silver halide emulsion containing at least one organic heterocyclic compound, having a high spectral sensitivity and a suitable spectral sensitivity distribution.

2. Description of the Prior Art it is well known that in making a photographic light-sensitive material a sensitizing dye is added to a silver halide photographic emulsion to thereby expand its spectral wavelength region towards the long wave length side, i.e., a spectral sensitizing technique is perfonned.

Spectral sensitivity is affected by the chemical structure of a sensitizing dye and by various properties of an emulsion, such as the halogen composition of the silver halide; crystal habit; crystal system; silver ion concentration; and the pH of the emulsion. The spectral sensitivity is also affected by additives present in an emulsion, such as a stabilizer, an antifoggant, a coating agent, a floculating agent, agents for modifying the physical properties of a film. In many cases, the spectral sensitivity of the film is lowered thereby.

A further technique has been known for making a light-sensitive material wherein two or more sensitizing dyes, or a sensitizing dye and an organic heterocyclic compound, are used in combination. In such a combination, there is often obtained a spectral sensitivity which is lower than either individual component. This is known as antisensitization. In certain special cases, however, the spectral sensitivity obtained by the use of a sensitizing dye in combination with one or more sensitizing dyes or organic heterocyclic compounds is superadditively" increased, much beyond the results obtained by the use of a single sensitizing dye. This is known as supersensitization.

It is also well known that the selection of the materials for such combinations of sensitizing dyes and organic heterocyclic compounds is critical, since supersensitization is markedly affected by a slight difference in the chemical structure of components. Thus, a suitable combination of a sensitizing dye or organic heterocyclic compound having a supersensitization effect is not predictable from chemical structural formula alone. An important problem is spectral sensitizing techniques is to find suitable combinations of sensitizing dyes and organic heterocyclic compounds which will give a supersensitizing action.

Ordinarily, a multilayer color light-sensitive material for subtractive color processes comprises a blue-sensitive emulsion layer, green-sensitive emulsion layer and red-sensitive emulsion layer. In the case of a multilayer color light-sensitive material for use in subtractive color process (used in cameras in particular), the distribution of the spectral sensitivity of emulsion layer is the main factor in determining the color reproducing character of the color light-sensitive material. It is required that a green-sensitive emulsion layer have a sensitivity which is as high as possible, that the maximum spectral sensitivity not occur in the long wavelengths and that a high spectral sensitivity be present only in the green region. It is known that, for example, 5,5 '-6,6- tetrachlorobenzimidazolocarbocyane (represented by the general formula I) shows a strong maximum in its spectral sensitivity based upon the J-absorption band at 583-585 millimicrons. However, this is not preferred from the angle of color reproduction.

In the case of a red-sensitive emulsion layer, it must lower the spectral sensitivity in the green region while raising the spectral sensitivity in the red region, because a panchromatic sensitizing dye is generally used. Moreover, the maximum wavelength of the spectral sensitivity is preferably not at the longer wavelength side, for example, longer than 670 millimicrons. The requirement of a red-sensitive emulsion is to have a high spectral sensitivity in the narrow red region.

SUMMARY OF THE INVENTION A silver halide photographic emulsion comprising at least one sensitizing dye represented by general formula 1:

wherein Z and Z, are atoms necessary to complete a heterocyclic ring selected from the group consisting of a benzimidazole ring, a benzothiazole ring, a naphthothiazole ring and a benzoselenazole ring; R and R are a member selected from the group consisting of an unsubstituted alkyl group, a substituted alkyl group, a monovalent aliphatic unsaturated hydrocarbon group and an aralkyl group; R is a member selected from the group consisting of a hydrogen atom and an alkyl group, said R being a hydrogen atom when Z and Z, are atoms forming benzimidazole ring; and X, is an anion group and at least one organic heterocyclic compound selected from the formulas represented by general formula ll and I], wherein general formula II is:

wherein Z, is the atoms necessary to complete a heterocyclic ring selected from the group consisting of a benzimidazole ring and a naphthoimidazole ring; R, is a member selected from the group consisting of an unsubstituted alkyl group. a substituted alkyl group, a monovalent aliphatic unsaturated hydrocarbon group and an aralkyl group; R is a member selected from the group consisting of a hydrogen atom and an alkylene group necessary to complete a ring when R and R, are bonded to form the ring; and A is a member selected from the group consisting of an unsubstituted phenyl group and a substituted phenyl group and general formula III is wherein X is an anion group and A, 2;, R and R have the same meaning as in general formula II.

It is the principal object of the present invention to provide a spectral sensitizing technique whereby the spectral sensitization of an ortho-chromatic sensitizing dye can be raised in a sufficiently narrow green region, while the spectral sensitization of a panchromatic sensitizing dye can be raised in sufficiently narrow red region.

BRIEF DESCRIPTION OF THE DRAWING H68. 1 and 2 illustrate the spectral sensitivity curves resulting from the cases of utilizing a sensitizing dye alone and also in combination with an organic heterocyclic compound.

DETAlLED DESCRIPTION OF THE lNVENTlON The object of the invention can be accomplished by adding to a silver halide photographic emulsion at least one sensitizing dye represented by general formula I, and at least one organic heterocyclic compound represented by the general formula II, or, at least one organic heterocyclic compound represented by general formula III, in combination.

General Formula I wherein Z, and Z, are atoms necessary to complete a benzimidazole ring, a benzothiazole ring, a naphthothiazole ring or a benzoselenazole ring; R, and R are an alkyl group, a substituted alkyl group, a monovalent aliphatic unsaturated hydrocarbon group or an aralkly group; R is a hydrogen atom or an alkyl group, said R being a hydrogen atom when Z, and 2 are the atoms to complete a benzimidazole ring; and X, is an anion group,

General Formula II wherein Z is the atoms necessary to complete a benzimidazole ring or a naphthoimidazole ring; R is an alkyl group, a substituted alkyl group, a monovalent aliphatic unsaturated hydrocarbon group or an aralkyl group; R represents hydrogen atoms or an alkylene group necessary t complete a ring when R and R are bonded to form the ring; and A is an unsubstituted or a substituted phenyl group.

General Formula 111 wherein X, is an anion group and A, 2,, R, and R have the same meaning as in the general formula II.

In these formulas, for example, R,, R and R, are an alkyl group such as methyl, ethyl or propyl group, a substituted alkyl group such as 2-hydroxyethyl, 2-methoxyethyl, carboxymethyl, 2-carboxyethyl, 3-carboxypropyl, 4-carb0xybutyl, 2- sulfoethyl, 3-sulfopropyl, 4-sulfobutyl, 3-sulfobutyl or a 2-carboethoxyethyl group, a monovalent aliphatic unsaturated hydrocarbon group such as an aryl group, and an aralkyl group. R is a hydrogen atom or an alkyl group such as methyl or ethyl group. With respect to Z,, Z, and Z the ring may be substituted with a substituent, for example, a halogen atom, cyano, trifluoromethyl, phenyl, carboalkoxy, alkyl, hydroxyl or alkoxy group. X, and X need not be present when the quaternary nitrogen atom and R, and R or R, form a betaine structure. The details thereof will be understood by making reference to the following examples of suitable compounds, which are not intended to limit the invention.

II s C H s 2 I CCH=CCH=O CH3 N N 5 (1 I I H2): Cz s C=CHCH=N C1 f 15 2 5 M.P. 151 C.

IIB 1115 C=OH-CH=N 0N i C2Hs M.P. 135 C.

:10 ung /c=oH -cH=N 01 CN y. 162 0.

IID CIhHb C=OHCH=N 01 (3H2 CH=CH M.P. 102 0.

IIE 11 C=CH-CH=N c1- cz s M.P. 234 0.

HF (5:15 I

/C=CHCH=NC a c1 I|-I 0,115 M.P. 134 c.

IIG I z s c=cH-oH=N--oom 01 I 7 01H: M.P. 116 0. 75

The organic heterocyclic compounds of the invention, represented by general formula II and Ill, can be synthesized by known methods. Compounds of general formula II can readily be obtained by treating compounds of the general formula III with an aqueous alkaline solution.

A typical synthesis of the compounds represented by general formulas II and III are shown by the following examples.

Synthesis Example 1:

C=CHCH=N Cl N zHs IIA 4.7 g. of 2-(beta-anilinovinyl)-5,6-dichloro-l,3diethylbenzimidazolium iodide was suspended in ml. of acetone and then a solution of 2 g. of caustic soda in 3 ml. of water was dropwise added thereto at room temperature while stirring. After 20 minutes, a large amount of water was added. A crystallized product was filtered, washed with water, dried and recrystallized in ligroine to give 1.2 g. of compound II melting at 151 C. The spectral absorption maximum wavelength thereof was 384 millimicrons (in methanol) Synthesis Example 2: amount of a methanol solution of a dye represented by the CZHS general formula II or ill, having a predetermined concentra- IlI tion, were added thereto and stirred. C1 Thereafter, the mixture was allowed to stand for 10 minutes 5 in a thermostatic heater at 37 C. and stirred to obtain a CCH=CHNH O1 complete emulsion. The obtalned emulslon was unlformly apfi Br plled onto a glass support in a proportion of 7.0 ml. per cabinet size, and then set and dried to obtain a sample of a CHICOOH 111D light-sensitive material.

3.5 g. of 1 carb0xymethy1 56 dichloro 3 ethyl 2 methyl l0 Optlcal wedge exposure of the sample was carried out by henzimidazolium bromide and 3.8 g. of diphenylformamidine the use of two sources: 8 havmg were heated and fused at 160 C. and reacted for 2 hours, the Perature of SAW obtaomed form a hght source having a reaction product being gradually solidified. After cooling, it Color temperaiure of 21666 through a DO converslon filter was crystallized with acetone and washed with acetone to and a yellow llght obtalned from the same but further filtered min 34 of compound HID melting at (decmm through No. 12 l 'ilter (Trade Mark, made by Fuji Photo Film posed). The spectral absorption maximum wavelength thereof Coo Ltd-)i P? only llght of a long Wavelength g was 384 millimicrons in methanol). than 500 mllllmlcroml a Compounds IIB, 11C, 11D, llE, HF, 11G, 11H, lllA, IllB, and T Sample was then developed at for 10 mmutes IlIC can be obtained by similar methods to the ones above Wlth f developer hereafter descnbed, Passed thfough 3510p described. 20 solutlon and a fixing solution and then washed wlth water to The sensitizing dye or organic heterocyclic compound used give a strip. The density thereof was measured by means of S- in the invention is dissolved inawater-soluble organic solvent, yp Densiiometef (Trade Mark, made y j Photo Film for example, methanol, ethanol, butanol or pyridine, and C0., Ltd.) to determine the degree of spectral sensitization. added to a silver halide photographic emulsion. The addition he standard optical density for determining the sensitivity may be carried out in solution form separately, or after being Was the P of! g denslty lmixed. The type of silver halide used in this photographic I The degrees of spectral sensltlzatlon are shown (relatively) emulsion may be silver bromide, silver iodobromide, silver table chlorobromide and silver chloroiodobromide. Into the silver A l' p Ofthe Same llgin'sensmw mater Obtamed P the halide emulsion there may be incorporated, in addition to the foregoing manner a sublecled to p l exposure "Sing a gelatin, a silver halide, a sensitizing dye and an organic heteroreflection-type 8 8 spectl'al and cyclic compound, a chemical sensitzer, a stabilizer an antifogdeveloped, descllbed abovei t0 g a p; Measurement gam, a coating agent, a photographic dye ff Such as an antiof the denslty thereof y elded aspectral sensltlvlty curve as irradiation dye, a filter dye or an antihalation dye, a binder Show" the accompanying drawmg- (besides gelatin) and, if necessary, a color former. 35

The invention will now be illustrated more specifically by H the following examPles- Composition of the developer used EXAMPLE 1 Water($0C.) 750 ml.

40 Motel 2 g.

A silver iodobromide gelatin emulsion prepared in the con- Anhydrous sodium sulfite I00 3. ventional manner was placed in a beaker and dissolved in a :Ydmqummc thermostatic heater at 40 C. A predetermined amount of a 111, L000 m methanol solution of a dye represented by the general formula 1 having a predetermined concentration and a predetermined TABLE 1 Amount of sensitizing Amount of super Relative sensitizing dye used, rnl. sensitizcr used, spectral max. wave- No. (molar couc.) m1. (molar cone.) speed Fog length (my) 1 I A(4X10- 4 0.10 583 I A(4X10- s 100 0.10 583 I A(4 10- 4 II E(4 10- 4 0.11 570 I A(4X10-4) 4 II E(4X10-4) s 125 0.14 564 2 I A(4 10 4 II F(4) 10-4) 4 141 0.14 568 I A(4x10 4 II F(4 10- s 141 0.13 560 I A(4 10- 4 II F(4 10- 16 178 0.20 558 3 I A(4 10- 4 II H(4X10 4 129 0.19 570 I A(4Xl0- 4 II H(4 10- s 118 0.21 563 4 I A(4X10 4 III A(4X10-4) 4 152 0.17 573 I A(4X10'4) 4 III A(4 10- s 141 0.18 578 I 2404x102 4 III A(4X10- 16 141 0.22 567 5 I A(4 10 4 III B(4X10- 2 132 0.10 570 I A(4 10- 4 III B(4 10 2 132 0.10 570 I A(4X10"*) 4 III B(4 1 H) 8 142 0.11 560 I A(4X10-4) 4 III 13(4x10 16 142 0. 08 560 6 I A(4 10- 4 III C(4 10- 2 118 0.10 572 I A(4 10 4 III c(4 10' 4 142 0.13 568 I A(4xl0- 4 III C(4X10- s 152 0.14 560 7 I C(4X10- l 100 0.13 572 I c(4 10- 118 0.17 572 I 0(4x10- s 100 0.20 572 I C(4X10- 4 II A(4 10- 4 126 0.20 560 I C(4X10- 4 II A(4X10- s 126 0.20 550 I C(4X10- 4 II B(4) l0- 4 126 0.20 560 I C(4X10- 4 II B(4X10-4) 4 141 0.14 540 I C(4X10 4 II B(4X10- 16 126 0.11 540 0 I D(4' 10 71 0.16 570 I D(4X104) 100 0.17 575 I D(4 10- s 100 0.18 575 I D(4 1O-4) 4 II A(4 I0- 4 141 0. 20 570 I D(4X1O" 4 II A(4 l0- s 166 0.17 560 TABLE 1 Amount of sensitizing Amount of super Relative sensitizing dye used, ml. sensitizer used, spectral max. wave- No. (molar cone.) m1. (molar cone.) speed Fog length (m 161T. 'IE(s 10- 60' "6.09 I 642 I E(8X10 85 0.10 642 I E(8X10- 8 100 0.14 642 I E(8X10- 4 II A(4X10- 4 110 0.18 630 I E(8X10- 4 II A(4X10- 8 118 0.18 625 I E(8X10- 4 II A(4X10- 16 132 0.12 620 1 I E(8X10- 4 II C(4X10- 4 142 0.15 635 I E(8X10- 4 II C(4X10 8 142 0.15 635 I E(8X10 4 II C(4X10' 16 152 0. 620

12 I F(8X10- 85 0.10 650 I F(8X10- 100 0.14 650 I F(8X1O- 100 0. 13 650 13 I F(8X10- 4 II C(4X10' 4 118 0.15 642 I F(8X10 II C(4X10' 8 141 0.16 630 I F(8X10- II C(4X10- 16 141 0.18 615 14 I G(8X10 100 0.13 640 I G(8X10' 115 0.15 640 I G(8X10 8 115 0.15 640 I G(8X10' 4 II A(4X10" 4 159 0.16 630 I G(8 10 4 II A(4 10- 8 166 0.17 625 I G(8X10* 4 II A(4X10- 16 200 0.12 625 15 I G(8X10- 4 II C(4X10- 4 166 0.15 635 I G(8X10' 4 II C(4X10' 8 200 0.15 625 I G(8X10- 4 II C(4X10 16 200 0.13 622 16 I .T(4X10 90 0.10 660 I J(4X10- 100 0.11 660 I J (4X10- 8 111 0.13 660 I J(4X10- 4 II A(4X 130 0.11 650 I J (4X10 4 II A(4X10' 8 135 0.11 645 EXAMPLEZ u 6 'I'he sample was subjected to optical wedge exposure or spectral exposure in a manner similar to that of example I, developed at 20 C. for 10 minutes by the use of a color developer containing a N,N'-diethyI-aminoparaaminoaniline derivative and then subjected to a first fixing, a bleaching, a second fixing and a washing with water to obtain a cyan negative image. The density thereof was secured with a red filter to estimate the relative spectral sensitizations thereof. The results are shown in table 2.

TABLE 2 Amount of sensitizing Amount of super Relative sensitizing dye used, ml. sensitizcr used, ml. spectral max. wave- No. (molar cone.) (molar cone.) speed Fog length (m) 17... I H(8X10 76 0. 08 650 I H(8X10 4 01 0. 10 655 I H(8 10- 8 100 0. 10 655 I H(8X10 4 142 0. 10 642 I H(8 10 4 142 0. 11 035 I H(8X10*) 4 142 0. 11 625 18 I H(8 10 4 118 0.10 640 I H(8X10-) 4 142 0. 11 630 I H(8X10 4 II G(4X10' 16 142 0. 11 620 NOTE.Cornposition oi the color forming developer used: G

N,N-diethylaminoparaaminoarnline sulfate 2.0 Sodium sulfite 2. 0 Sodium carbonate (monohydrate) Hydroxylamine hydroehloride 1. 5 Potassium bromide 1. 0

Water to 1,000 ml.

the mixture stirred. Thereafter, the mixture was neutralized FIG. 1 and FIG. 2 of the drawing show the spectral sensitiviwith citric acid to a pH of 6.5. A hardener and surface active ty curves in the cases of using a sensitizing dye alone and with agent (for coating) were then added thereto, and the resultant solution coated onto a film support, and dried, to obtain a sample of a red-sensitive color sensitive material.

l S OaNa an organic heterocyclic compound for comparison. In FIG. 1, Curve I is a spectral sensitivity curve resulting from using 4 ml. of IA (4Xl0 molar concentration) alone per g. of the photographic emulsion, Curve II is that for using 4 ml. of HF (4xl0molar concentration) alone, and Curve Ill and Curve IV are those resulting from using 4 ml. of the foregoing IA with 4 ml. and 8 ml., respectively, of the foregoing IIF in example I. In FIG. 2, Curve V is a spectral sensitivity curve resulting upon using 4 ml. of IH (4Xl0 molar concentration alone per 100 g. of the photographic emulsion, and Curve VI and Curve VII are the curves resulting from using 4 ml. of the foregoing III with 4 ml. and 8 ml., respectively, of 118 (4X10 molar concentration) in combination, as in example 2.

To further illustrate the preferred form of the present invention, the dye represented by general 7 formula I is generally present in amounts of from about lXl mole to about 0.40 mole per kilogram of silver halide emulsion. Further, the amount of the materials represented by general formulas ll or III will generally range from about l to about 5 times the amount of the dye represented by general formula 1 (molar basis).

Further, in the compounds represented, the alkyl group per se, as for example represented by R,, has from one to five carbon atoms.

What is claimed is:

l. A silver halide photographic emulsion containing from 1X10" to 0.4 mole, per kg. of said emulsion, of at least one sensitizing dye represented by the following formula I:

wherein Z and Z are the atoms necessary to complete a heterocyclic ring selected from the group consisting of a benzimidazole ring, a benzothiazole ring, a naphthothiazole ring and a benzoselenazole ring; R and R are a member selected from the group consisting of an alkyl group of one to five carbon atoms, a substituted alkyl group wherein the alkyl group has from one to five carbon atoms and wherein the substituent is hydroxy, alkoxy having from one to five carbon atoms, carboxy, sulfoor carboxy-alkoxy wherein the alkoxy group has from one to five carbon atoms, an aryl group and an aralkyl group wherein the alkyl moiety has from one to five carbon atoms; R; is a member selected from the group consisting of a hydrogen atom and an alkyl group having from one to five carbon atoms, said R being a hydrogen atom when 2, and Z, are atoms forming a benzimidazole ring; and X, is an acid anion group; and at least one organic hetercyclic compound of formulas H or lll, wherein formula II is:

heterocyclic ring selected from the group consisting of a benzimidazole ring and a naphthoimidazole ring; R is a member selected from the group consisting of an alkyl group having from one to five carbon atoms, a substituted alkyl group wherein the alkyl group has from one to five carbon atoms and wherein the substituent is hydroxy, alkoxy of one to five carbon atoms, carboxy, sulfoor carboxy-alkoxy wherein the alkoxy moiety has from one to five carbon atoms, an aryl group and an aralkyl group wherein the alkyl moiety has from one to five carbon atoms; R, is a member selected from the group consisting of a hydrogen atom and an alkylene group necessary to complete a ring when R. and R are bonded to form the ring; and A is a member selected from the group consisting of phenyl and substituted phenyl; wherein formula III is:

wherein X is an acid anion group, and A, 2 R and R have the same meaning as in formula ll, wherein said heterocyclic compound is present in an amount of from 1/10 to 5 times the amount of said sensitizing dye, on a molar basis.

2. A silver halide photographic emulsion as claimed in claim 1, wherein said sensitizing dye represented by the general formula 1 is a member selected from the group consisting of:

l C z);

and 0,115

| f N L) I Ds 02115 3 115 and 3. A silver halide photographic emulsion as claimed in claim 02115 1, wherein said organic heterocyclic compound represented i; by general formula ll is a member selected from the group consisting of: C=C CH= Q Cl E2115 15 0H, CHE-CH; C1

U C=CH CH=N C1 f CgHs CgHfi l 4. A silver halide photographic emulsion as claimed in claim 1, wherein said organic heterocyclic compound represented C=CH OH=N@ by the general formula III is a member selected from the group consisting of: ON

f C1115 CgHs /N C CH=CH NH f Cl- C H N and I C 2H5 (1) 115 CgHs CH C O OH Br- CzHs 

2. A silver halide photographic emulsion as claimed in claim 1, wherein said sensitizing dye represented by the general formula 1 is a member selected from the group consisting of:
 3. A silver halide photographic emulsion as claimed in claim 1, wherein said organic heterocyclic compound represented by general formula II is a member selected from the group consisting of:
 4. A silver halide photographic emulsion as claimed in claim 1, wherein said organic heterocyclic compound represented by the general formula III is a member selected from the group consisting of: 